This is a Phase 2, randomized, double-blind, vehicle-controlled study to assess the efficacy and safety of CLE-400 topical gel for the treatment of chronic pruritus in adult subjects with Notalgia Paresthetica (NP).

Study to assess the efficacy and safety of CLE-400 topical gel applied once daily for the treatment of moderate-severe chronic pruritus in adult subjects with NP. The study comprises a screening phase of up to 37 days, including a 7-day run-in period, a 4-week double-blind treatment period, and a 2-week follow-up period.

Inclusion Criteria:

• Subject has a confirmed diagnosis of Notalgia Paresthetica.
• Subject has a history of chronic pruritus (itch) due to Notalgia Paresthetica.
• Subject has moderate to severe pruritus.
• Subject is able and competent to read and sign the informed consent form (ICF).

Exclusion Criteria:

• Subject has chronic pruritus that is related to a condition other than Notalgia Paresthetica.
• Subject with known or suspected history of a clinically significant systemic disease, unstable medical disorders, life-threatening disease, including physical/laboratory/ECG/vital signs abnormality that would put the subject at undue risk or interfere with interpretation of study results
• Subject is a female who is breastfeeding, pregnant, or who is planning to become pregnant during the study.

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